Method for forming hybrid-bonding structure

ABSTRACT

A method for forming a hybrid-bonding structure is provided. The method includes forming a first dielectric layer over a first semiconductor substrate. The first semiconductor substrate includes a conductive structure. The method also includes partially removing the first dielectric layer to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern and an opening through the first dielectric layer. The first dielectric dummy pattern, the second dielectric dummy pattern and the third dielectric dummy pattern are surrounded by the opening. In addition, the method includes forming a first conductive line in the opening. The first conductive line is in contact with the conductive structure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of U.S. patent application Ser. No. 15/462,078, filed on Mar. 17, 2017, the entirety of which is incorporated by reference herein.

BACKGROUND

The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased.

Three dimensional integrated circuits (3DICs) are a recent development in semiconductor packaging in which multiple semiconductor dies are stacked upon one another, such as package-on-package (PoP) and system-in-package (SiP) packaging techniques. Some 3DICs are prepared by placing dies over dies on a wafer level. 3DICs provide improved integration density and other advantages, such as faster speeds and higher bandwidth, because of the decreased length of interconnects between the stacked dies, for example. However, there are many challenges related to 3DICs.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It should be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIGS. 1A-1E are cross-sectional views of various stages of a process for forming a hybrid-bonding structure, in accordance with some embodiments;

FIG. 2 is a cross-sectional view of a hybrid-bonding structure, in accordance with some embodiments;

FIG. 3 is a plane view of a structure for forming a hybrid-bonding structure as shown in FIG. 1D and FIG. 2, in accordance with some embodiments; and

FIGS. 4A-4M are plane views showing arrangements of dielectric dummy patterns embedded in the conductive line structure of a structure for forming a hybrid-bonding structure, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows includes embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. The present disclosure may repeat reference numerals and/or letters in some various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between some various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

Some embodiments of the disclosure are described. Additional operations can be provided before, during, and/or after the stages described in these embodiments. Some of the stages that are described can be replaced or eliminated for different embodiments. Additional features can be added to the semiconductor device structure. Some of the features described below can be replaced or eliminated for different embodiments. Although some embodiments are discussed with operations performed in a particular order, these operations may be performed in another logical order.

Other features and processes may also be included. For example, testing structures may be included to aid in the verification testing of the 3D packaging or 3DIC devices. The testing structures may include, for example, test pads formed in a redistribution layer or on a substrate that allows the testing of the 3D packaging or 3DIC, the use of probes and/or probe cards, and the like. The verification testing may be performed on intermediate structures as well as the final structure. Additionally, the structures and methods disclosed herein may be used in conjunction with testing methodologies that incorporate intermediate verification of known good dies to increase the yield and decrease costs.

Embodiments for a hybrid-bonding structure and a method for forming the hybrid-bonding structure are provided. FIGS. 1A-1E are cross-sectional views of various stages of a process for forming a hybrid-bonding structure 600A, in accordance with some embodiments. As shown in FIG. 1A, a substrate 100 is received in accordance with some embodiments. The substrate 100 may be a semiconductor wafer such as a silicon wafer. In some embodiments, the substrate 100 includes elementary semiconductor materials, compound semiconductor materials, and/or alloy semiconductor materials. Examples of the elementary semiconductor materials may be, but are not limited to, crystal silicon, polycrystalline silicon, amorphous silicon, germanium, and/or diamond. Examples of the compound semiconductor materials may be, but are not limited to, silicon carbide, gallium arsenic, gallium phosphide, indium phosphide, indium arsenide, and/or indium antimonide. Examples of the alloy semiconductor materials may be, but are not limited to, SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, and/or GaInAsP. In some embodiments, the substrate 200 includes an epitaxial layer. For example, the substrate 200 has an epitaxial layer overlying a bulk semiconductor.

The substrate 100 may include various doped regions such as p-type wells or n-type wells). Doped regions may be doped with p-type dopants, such as boron or BF₂, and/or n-type dopants, such as phosphorus (P) or arsenic (As). The doped regions may be formed directly on the substrate 100, in a P-well structure, in an N-well structure or in a dual-well structure.

In some embodiments, the substrate 100 includes a circuit region 104 a and a seal ring region 104 b surrounding the circuit region 104 a. In some embodiments, the substrate 100 includes one or more integrated circuit structures 102 formed in the circuit region 104 a of the substrate 100. The integrated circuit structure 102 may include transistors (e.g., metal oxide semiconductor field effect transistors (MOSFET), complementary metal oxide semiconductor (CMOS) transistors, bipolar junction transistors (BJT), high-voltage transistors, high-frequency transistors, p-channel and/or n-channel field effect transistors (PFETs/NFETs), etc.), diodes, and/or other applicable elements. Various processes are performed to form the integrated circuit structure 102, such as deposition, etching, implantation, photolithography, annealing, and/or other applicable processes. In some embodiments, the integrated circuit structure 102 is formed in the substrate 100 in a front-end-of-line (FEOL) process.

In some embodiments, the substrate 100 further include one or more isolation features 101 formed in the circuit region 104 a, such as shallow trench isolation (STI) features or local oxidation of silicon (LOCOS) features. The isolation features 101 may surround the integrated circuit structure 102. The isolation features 101 are configured to provide physical and electrical isolation between the integrated circuit structure 102 and other integrated circuit structures (not shown).

In some embodiments, the substrate 100 includes a seal ring structure 114 formed in the seal ring region 104 b. In some embodiments, the seal ring structure 114 is formed in a dielectric layers 106 (such as interlayer dielectric (ILD) or an inter-metal dielectric (IMD) layer). The dielectric layer 106 may include a single layer or multiple dielectric layers. In some embodiments, the dielectric layer 106 is made of silicon oxide, silicon oxynitride, un-doped silicate glass (USG), borosilicate glass (BSG), phosphoric silicate glass (PSG), borophosphosilicate glass (BPSG), fluorinated silicate glass (FSG), low-k material, porous dielectric material, or a combination thereof. In some embodiments, the dielectric layer 106 is formed by a chemical vapor deposition (CVD) process, a spin-on process, a sputtering process, or a combination thereof.

In some embodiments, the dielectric layer 106 is made of an extreme low-k (ELK) dielectric material with a dielectric constant (k) less than about 2.5. With geometric size shrinking as technology nodes advance to 30 nm and beyond, ELK dielectric material is used to minimize device RC (time constant, R: resistance, C: capacitance) delay. In some embodiments, ELK dielectric materials include carbon doped silicon oxide, amorphous fluorinated carbon, parylene, bis-benzocyclobutenes (BCB), polytetrafluoroethylene (PTFE) (Teflon), or silicon oxycarbide polymers (SiOC). In some embodiments, ELK dielectric materials include a porous version of an existing dielectric material, such as hydrogen silsesquioxane (HSQ), porous methyl silsesquioxane (MSQ), porous polyarylether (PAE), porous SiLK, or porous silicon oxide (SiO₂). In some embodiments. ELK dielectric material is deposited by a plasma enhanced chemical vapor deposition (PECVD) process or by a spin coating process.

In some embodiments, the seal ring structure 114 includes conductive layers 112 and vias 108 formed in the dielectric layer 106. In some embodiments, the seal ring structure 114 is formed by repeatedly stacking the conductive layers 112 and the vias 108 on top of each other. The vias 108 are alternately arranged with the conductive layers 112. In some embodiments, the seal ring structure 114 is formed continuously surrounding the circuit region 104 a. The seal ring structure 114 may serve as a barrier for preventing contaminants such as moisture, chemicals, corrosive material or etc. from penetrating into the substrate 100 and preventing cracks from propagating into the substrate 100 upon die-sawing operations. In some embodiments, the seal ring structure 114 is electrically isolated from the integrated circuit structure 102.

The conductive layers 112 and the vias 108 may be made of a conductive material, such as copper (Cu), aluminum (Al), tungsten (W), titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), or another applicable material. In some embodiments, the conductive layers 112 and the vias 108 are copper or copper alloy. In some embodiments, the conductive layers 112 and the vias 108 are formed by single and/or dual damascene processes. The conductive layers 112 may include multiple metal layers (namely M1, M2, M3 . . . , and Mtop) which are interconnected through the vias 108. In some embodiments, another metal line and another via are formed over and electrically connected to the conductive layers 112 and the vias 108. The conductive layers 112 and the vias 108 of the seal ring structure 114 are formed in a back-end-of-line (BEOL) process.

After the seal ring structure 114 is formed, a dielectric layer 118 and a dielectric layer 120 are sequentially formed over a substrate 100, as shown in FIG. 1A in accordance with some embodiments. The dielectric layer 118 and the dielectric layer 120 are formed covering a top surface 115 of the seal ring structure 114. In some embodiments, the dielectric layer 118 and the dielectric layer 120 may collectively serve as a dielectric layer structure 113. In some embodiments, the dielectric layer 118 and the dielectric layer 120 are formed of insulating material such as oxide based materials including silicon oxide (SiO₂), silicon oxynitride (SiON), silicon oxycarbon nitride (SiOCN) or other insulting materials. In some embodiments, the dielectric layer 118 is formed of an insulating material that is different from the dielectric layer 120. In some embodiments, the dielectric layer 118 is formed of SiO₂, the dielectric layer 120 is formed of SiON or SiOCN. In some embodiments, the dielectric layer 118 and the dielectric layer 120 are formed by performing a plasma enhanced chemical vapor deposition (CVD) process, a low pressure CVD process, an atomic layer deposition (ALD) process, or another applicable process.

After the dielectric layer 118 and the dielectric layer 120 are formed, a patterning process 122 is performed to form dielectric dummy patterns 150 and openings 124 through the dielectric layer 118 and the dielectric layer 120, as shown in FIG. 1B in accordance with some embodiments. In some embodiments, positions of the openings 124 provide a position of a conductive line formed in the subsequent processes. The conductive line is configured to hybrid-bond with another conductive line of another semiconductor structure. The dielectric dummy patterns 150 and the openings 124 are formed directly over the topmost conductive layer 112 of the seal ring structure 114. In some embodiments, portions of the topmost conductive layer 112 (located at the topmost metal layer Mtop) of the seal ring structure 114 are exposed by the openings 124. The dielectric dummy patterns 150 are surrounded by the openings 124.

In some embodiments, the patterning process 122 includes a photolithography process and a subsequent etching process. In some embodiments, the etching process is a dry etching process. In some embodiments, etching gases used in the etching process include fluorine-containing (F-containing) gases. During the etching process, portions of the dielectric layer structure 113 is removed through an opening of an etching mask (not shown) formed by the photolithography process, and the etching process stops when the topmost conductive layer 112 of the seal ring structure 114 is exposed.

After the dielectric dummy patterns 150 and the openings 124 are formed, a seed layer 128 is conformally formed over the dielectric layer structure 113. The seed layer 128 is formed lining the openings 124 to assist the formation of a conductive material for forming a conductive line in the subsequent processes. In some embodiments, the seed layer 128 is made of copper-containing conductive materials. In some embodiments, the seed layer 128 is formed by a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, or another applicable process. In some embodiments, the seed layer 128 has a thickness in a range from about 10 Å to about 500 Å

After the seed layer 128 is formed, a conductive material 130 is formed over the dielectric layer structure 113, as shown in FIG. 1C in accordance with some embodiments. The conductive material 130 is deposited to fill the openings 124. In some embodiments, the conductive material 130 is made of copper (Cu), aluminum (Al), aluminum copper (ACu), cobalt (Co), tungsten (W), or another applicable material. In some embodiments, the conductive material 130 is made of copper (Cu) or copper alloy. In some embodiments, the conductive material 130 is formed by a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, or another applicable process. In some embodiments, the conductive material 130 is formed by a plating method.

In some embodiments, a barrier layer (not shown) is deposited over the dielectric layer structure 113 to line openings 124 before forming the seed layer 128 and the conductive material 130. The barrier layer is configured to separate the conductive material 130 from the dielectric layer structure 113. In some embodiments, the barrier layer is made of titanium (Ti), titanium alloy, tantalum (Ta) or tantalum alloy. In some embodiments, the barrier layer is formed by a physical vapor deposition (PVD) process, an atomic layer deposition (ALD) process, or another applicable process. In some embodiments, the barrier layer has a thickness in a range from about 50 Å to about 1000 Å.

After the conductive material 130 is formed, a planarization process 131 is performed on the conductive material 130 and the seed layer 128 above the dielectric layer structure 113, as shown in FIG. 1D in accordance with some embodiments. The planarization process 131 is performed to remove the conductive material 130 and the seed layer 128 above the dielectric layer structure 113 and outside the openings 124. The planarization process 131 is performed until the dielectric layer structure 113 is exposed. In some embodiments, the planarization process 131 includes an etch-back process and/or a chemical mechanical polishing (CMP) process.

After performing the planarization process 131, a conductive line 132 is formed in the openings 124. In some embodiments, the seed layer 128 merges with the conductive line 132 to form a conductive line 134 in the openings 124.

After performing the aforementioned processes, a structure 500 a of the hybrid-bonding structure 600A is formed, as shown in FIG. 1D in accordance with some embodiments. FIG. 3 is a plane view of the structure 500 a of the hybrid-bonding structure 600A as shown in FIG. 1D, in accordance with some embodiments.

As shown in FIG. 1D, in some embodiments, the conductive line 132 (or the conductive line 134) is formed directly over the seal ring structure 114. The conductive line 132 is electrically connected to the topmost conductive layer 112 of the seal ring structure 114. In some embodiments, the conductive line 132 (or the conductive line 134) serves as a bonding layer of the seal ring structure 114 of the structure 500 a.

As shown in FIG. 1D and FIG. 3, in some embodiments, the dielectric dummy patterns 150 are formed embedded in the conductive line 132 (or the conductive line 134). In some embodiments, top surfaces 138 of the dielectric dummy patterns 150 are aligned with a top surface 136 of the conductive line 132 (or the conductive line 134). In some embodiments, the top surfaces 138 of the dielectric dummy patterns 150 and the top surface 136 of the conductive line 134 may serve as a bonding surface 154 of the semiconductor structure 500 a of the hybrid-bonding structure 600A. In some embodiments, the top surfaces 138 of the dielectric dummy patterns 150 and the top surface 136 of the conductive line 134 are exposed for hybrid-bonding with another conductive line of another semiconductor structure.

In some embodiments, the dielectric dummy patterns 150 are formed in the seal ring region 104 b and directly over the seal ring structure 114. Sidewalls 152 and bottom surfaces 139 of the dielectric dummy patterns 150 are surrounded by the conductive line 134 and the topmost conductive layer 112 of the seal ring structure 114. In some embodiments, there is no semiconductor device element formed within the dielectric dummy patterns 150. In addition, there is no semiconductor device element formed between the dielectric dummy patterns 150 and the conductive line 134. Furthermore, there is no semiconductor device element formed between the dielectric dummy patterns 150 and the topmost conductive layer 112 of the seal ring structure 114.

In some embodiments, the dielectric dummy patterns 150 are formed over the seal ring structure 114 and surrounded by the conductive line 134 shown in FIG. 1D and FIG. 3. The dielectric dummy patterns 150 are formed between an inner boundary 142 a and an outer boundary 142 b of the conductive line 134. In some embodiments, the total area of the top surfaces 150 of the dielectric dummy patterns 150 is less than, equal to or greater than the area of the top surface 136 of the conductive line 134 in a plan view shown in FIG. 3.

In some embodiments, each of the dielectric dummy patterns 150 has a length La and a width Wa shown in FIG. 3. In some embodiments, the length La of each of the dielectric dummy patterns 150 is less than or equal to the total length of the conductive line 134. In some embodiments, the width Wa of each of the dielectric dummy patterns 150 is less than a width Wb of the conductive line 134.

In some embodiments, the dielectric dummy patterns 150 may have a circular-shape, an oval-shape, a polygonal-shape, or a ring-shape from a plane view. In some embodiments, the dielectric dummy patterns 150 are rectangular, as shown in FIG. 3. In some embodiments, the dielectric dummy patterns 150 are arranged substantially along an extending direction of the conductive line 134. In some embodiments, when the conductive line 134 is arranged as a ring (a rectangular ring), the dielectric dummy patterns 150 are collectively arranged as a dash-ring, as seen in the plan view shown in FIG. 3.

Afterwards, a structure 500 a′ similar to or the same as the structure 500 a formed by the aforementioned processes shown in FIG. 1A to FIG. 1E are bonded to the structure 500 a vertically to form the hybrid-bonding structure 600A by performing a hybrid-bonding process, as shown in FIG. 1E in accordance with some embodiments. The structure 500 a′ is flipped upside down to facilitate the conductive line 134 of the structure 500 a′ hybrid-bonded to the conductive line 134 of the structure 500 a. The substrate 100 of the structure 500 a′ is separated from the substrate 100 of the structure 500 a through the conductive line 134 of the structure 500 a and the conductive line 134 of the structure 500 a′. The conductive line 134 of the structure 500 a is aligned with and in contact with the conductive line 134 of the structure 500 a′. In some embodiments, the topmost conductive layer 112 of the seal ring structure 114 and the conductive line 134 of the structure 500 a, and the topmost conductive layer 112 of the seal ring structure 114 and the conductive line 134 of the structure 500 a′ encapsulate the dielectric dummy patterns 150 of the structure 500 a and the dielectric dummy patterns 150 of the structure 500 a′. In some embodiments, the dielectric dummy patterns 150 of the structure 500 a are in contact with the dielectric dummy patterns 150 and/or the conductive line 134 of the structure 500 a′.

In some embodiments, the conductive line 134 of the structure 500 a and the conductive line 134 of the structure 500 a′ for hybrid-bonding have the dielectric dummy patterns 150 embedded in the conductive line 134. The dielectric dummy patterns 150 can contribute to the bond strength between the conductive line 134 of the structure 500 a′ and the conductive line 134 of the structure 500 a of the hybrid-bonding structure 600A. Because the dielectric dummy patterns 150 are embedded in the conductive line 134, the area of the top surface 136 of the conductive line 134 can be reduced to improve the CMP loading effect during the planarization process (such as the CMP process) while the conductive line 134 has a wide width Wb. Therefore, the top surfaces 138 of the dielectric dummy patterns 150 are easy to make coplanar with the top surface 136 of the conductive line 134, and the bonding surface 154 of the structure 500 a has a planarized surface topography. As a result, the bonding wave propagation is improved during the hybrid-bonding process. The delamination problem and the conductive line opening problem that occurs between the bonding surface 154 of the structure 500 a′ and the bonding surface 154 of the structure 500 a are avoided.

FIG. 2 is a cross-sectional view of a hybrid-bonding structure 600B, in accordance with some embodiments. FIG. 3 is a plane view of the structure 500 b of the hybrid-bonding structure 600B as shown in FIG. 2, in accordance with some embodiments. In some embodiments, the plane view of the structure 500 b is similar to or the same as the plan view of the structure 500 a shown in FIG. 3. The materials, configurations, structures and/or processes utilized in the following embodiment are similar to those employed in FIGS. 1A to 1E and are not repeated herein.

In some embodiments, the hybrid-bonding structure 600B is a micro-electro-mechanical system (MEMS) device structure. The hybrid-bonding structure 600B includes a first structure 500 b, a second structure 300 and a third structure 400. The second structure 300 is hybrid-bonded to the first structure 500 b, and the third structure 400 is hybrid-bonded to the second structure 200.

In some embodiments, the first structure 500 b includes a first substrate 200, an interconnect structure 214 over the first substrate 200 and a conductive line 134 over the interconnect structure 214. In some embodiments, the first substrate 200 is a complementary metal-oxide (CMOS) semiconductor substrate. The first substrate 200 may be a semiconductor wafer such as a silicon wafer. In some embodiments, the first substrate 200 may include elementary semiconductor materials, compound semiconductor materials, and/or alloy semiconductor materials. Examples of the elementary semiconductor materials may be, but are not limited to, crystal silicon, polycrystalline silicon, amorphous silicon, germanium, and/or diamond. Examples of the compound semiconductor materials may be, but are not limited to, silicon carbide. gallium arsenic, gallium phosphide, indium phosphide, indium arsenide, and/or indium antimonide. Examples of the alloy semiconductor materials may be, but are not limited to, SiGe. GaAsP. AlInAs. AlGaAs. GaInAs. GaInP, and/or GaInAsP. In some embodiments, the first substrate 200 includes an epitaxial layer. For example, the first substrate 200 has an epitaxial layer overlying a bulk semiconductor. In some embodiments, the first substrate 200 includes one or more integrated circuit structures 102 formed over the first substrate 200 in a front-end-of-line (FEOL) process.

In some embodiments, the interconnect structure 214 is formed over the first substrate 200. In some embodiments, the interconnect structure 214 is electrically connected to the integrated circuit structure 102. The interconnect structure 214 includes multiple conductive layers 212 and vias 208 formed in the dielectric layer 106. In some embodiments, the interconnect structure 214 is formed by repeatedly stacking the conductive layers 212 and the vias 208 on top of each other. The vias 208 are alternately arranged with the conductive layers 212.

The conductive layers 212 and the vias 208 may be made of a conductive material, such as copper (Cu), aluminum (Al), tungsten (W), titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), or another applicable material. In some embodiments, the conductive layers 212 and the vias 208 are copper or copper alloy. In some embodiments, the conductive layers 212 and the vias 208 are formed by single and/or dual damascene processes. The conductive layers 212 may include multiple metal layers (namely M1, M2, M3 . . . , and Mtop) which are interconnected through the vias 208. In some embodiments, another metal line and another via are formed over and electrically connected to the conductive layers 212 and the vias 208. The conductive layers 212 and the vias 208 of the interconnect structure 214 are formed in a back-end-of-line (BEOL) process.

The dielectric layer structure 113 is formed over the interconnect structure 214. The dielectric layer structure 113 may include a single layer structure or multiple dielectric layer structure. In some embodiments, the dielectric layer structure 113 is formed of insulating material such as oxide based materials including silicon oxide (SiO₂), silicon oxynitride (SiON), silicon oxycarbon nitride (SiOCN) or other insulting materials.

The conductive line 134 is formed through the dielectric layer structure 113. The conductive line 134 is formed directly over the topmost conductive layer 212 of the interconnect structure 214. The conductive line 134 is electrically connected to the topmost conductive layer 212 of the interconnect structure 214. In addition, the conductive line 134 is electrically connected to the integrated circuit structure 102.

The dielectric dummy patterns 150 are formed embedded in the conductive line 134. The dielectric dummy patterns 150 are formed directly over the topmost conductive layer 212 of the interconnect structure 214. In some embodiments, the conductive line 132 serves as a bonding layer of the interconnect structure 214 of the first structure 500 b. In addition, the conductive line 134 serves as a bonding layer structure of the interconnect structure 214 of the first structure 500 b. In some embodiments, the dielectric dummy patterns 150 are surrounded by the conductive line 134 in a plan view shown in FIG. 3. The configuration, dimensions, shape, and arrangement of the dielectric dummy patterns 150 of the first structure 500 b may be similar to, or the same as, those of the dielectric dummy patterns 150 of the structure 500 a, and the details thereof are not repeated herein.

In some embodiments, the top surfaces of the dielectric dummy patterns 150 are coplanar with the top surface of the conductive line 134, and the bonding surface 154 of the first structure 500 b has a planarized surface topography.

The second structure 300 is hybrid-bonded to the first structure 500 b as shown in FIG. 2, in accordance with some embodiments. In some embodiments, the second structure 300 includes a second substrate 302 and bonding layers 220 and 222 formed over the second substrate 302. The second substrate 302 in a middle position of the hybrid-bonding structure 600B is configured to as a MEMS substrate. The second substrate 302 includes a moveable element 302 a and a fixed element 302 b surrounding the moveable element 302 a.

In some embodiments, the second substrate 302 may be made of silicon (Si), silicon-based materials or other semiconductor materials, such as germanium (Ge). In some embodiments, the second substrate 302 is a semiconductor substrate, such as a silicon (Si) wafer. In some embodiments, the second substrate 302 is made of a compound semiconductor such as silicon carbide, gallium arsenic, indium arsenide, or indium phosphide. In some embodiments, the second substrate 302 is made of semiconductor material, ceramic material, polymer material, metal material, another applicable material or a combination thereof.

The bonding layer 220 is formed on a bonding surface 304 of the fixed element 302 b of the second substrate 302. The bonding layer 222 is formed on a bonding surface 306 of the fixed element 302 b of the second substrate 302. The bonding surface 304 is opposite to the bonding surface 306. The second substrate 302 of the second structure 300 can be hybrid-bonded to another substrate by using the bonding layer 220 and bonding layer 222 as bonding materials. The second substrate 302 is hybrid-bonded to the first substrate 200 by bonding the bonding layer 220 of the second structure 300 to the conductive line 134 of the first structure 500 b as shown in FIG. 2. The first substrate 200 of the first structure 500 b is separated from the second substrate 302 of the second structure 300 through the conductive line 134 of the first structure 500 b and the first structure 500 b. The conductive line 134 of the first structure 500 b is aligned with and in contact with the bonding layer 220 of the second structure 300. In some embodiments, the topmost conductive layer 212 of the interconnect structure 214 and the bonding layer 220 of the second structure 300 encapsulate the dielectric dummy patterns 150 of the first structure 500 b. In some embodiments, the dielectric dummy patterns 150 of the first structure 500 b is in contact with the bonding layer 220 of the second structure 300.

The bonding layer 220 and bonding layer 222 are made of conductive material, such as metal material. In some embodiments, the bonding layer 220 is made of germanium (Ge), aluminum (Al), copper (Cu), titanium (Ti), tantalum (Ta), silver (Ag), gold (Au), nickel (Ni), indium (In), tin (Sn), or a combination thereof. The bonding layer 220 is formed by a chemical vapor deposition (CVD) process, a physical vapor deposition (PVD) process, a plating process, or another applicable process.

The third structure 400 is hybrid-bonded to the second structure 300 as shown in FIG. 2, in accordance with some embodiments. In some embodiments, the third structure 400 is flipped upside down and bonded to the second structure 300. In some embodiments, the third structure 400 includes a third substrate 402 and a bonding layer 422 formed over the third substrate 402. The third substrate 402 is configured as a cap substrate. In some embodiments, the material of the third substrate 402 of the third structure 400 may be the same as the material of the second substrate 302 of the second structure 300.

The third structure 400 is hybrid-bonded to the second structure 300 by bonding the bonding layer 422 of the third structure 400 to the bonding layer 222 of the second structure 300 as shown in FIG. 2. The bonding layer 422 of the third structure 400 is aligned with and in contact with the bonding layer 220 of the second structure 300. Some materials and processes used to form the bonding layer 422 of the third structure 400 may be similar to, or the same as, those used to form bonding layer 220 and bonding layer 222 of the second structure 300 and are not repeated herein.

FIGS. 4A-4M are plane views showing the arrangement of the dielectric dummy patterns 150 a-150 k embedded in the conductive line 134 of structures 500 c-500 n and a structure 500 p, in accordance with some embodiments. The materials, configurations, structures and/or processes of portions below the conductive lines 134 of the structure 500 c-500 n and 500 p may be similar to, or the same as, those of structure 500 a and the first structure 500 b, and the details thereof are not repeated herein. The dielectric dummy patterns embedded in a single conductive line 134 are separated from each other. The dielectric dummy patterns 150 a-150 k shown in FIGS. 4A-4M are merely examples and are not intended to be limiting the shapes and the arrangements of the dielectric dummy patterns of the present disclosure.

As shown in FIG. 4A and FIG. 4B, in some embodiments, each of the dielectric dummy patterns 150 a embedded in the conductive line 134 of the structure 500 c or the structure 500 d is formed extending along the extending direction of the conductive line 134. The dielectric dummy patterns 150 a are parallel to each other and form continuous concentric rings. The inner boundary 142 a and the outer boundary 142 b of the conductive line 134 is parallel to a boundary 152 a of each of the dielectric dummy patterns 150 a. Each of the dielectric dummy patterns 150 a has a length that is equal to the total length of the conductive line 134. In addition, each of the dielectric dummy patterns 150 a has a single width W1 that is less than the width Wb of the conductive line 134 shown in FIG. 3.

As shown in FIG. 4C, in some embodiments, each of the dielectric dummy patterns 150 b embedded in the conductive line 134 of the structure 500 e is formed extending along the extending direction of the conductive line 134. One of the differences between the dielectric dummy patterns 150 a and the dielectric dummy patterns 150 b is that the dielectric dummy patterns 150 b have a first width W2 and a second width W3 that is different from the first width W2. In some embodiments, the opposite boundaries 152 b 1 and 152 b 2 of each of the dielectric dummy patterns 150 b are not parallel to each other. In addition, boundaries 152 b 1 of the dielectric dummy patterns 150 b that are close to each other are parallel to each other. In some embodiments, a portion 136 b of the top surface 136 has a zigzag shape.

As shown in FIG. 4D and FIG. 4E, in some embodiments, each of the dielectric dummy patterns 150 c embedded in the conductive line 134 of the structure 500 f or the structure 500 g is formed extending along the extending direction of the conductive line 134. The dielectric dummy patterns 150 c have a first width W4 and a second width W5 that is different from the first width W2. In some embodiments, the boundaries 152 c 2 of the dielectric dummy patterns 150 c are parallel to each other. In addition, boundaries 152 c 1 of the dielectric dummy patterns 150 c close to each other are parallel to each other. As shown in FIG. 4E, a dielectric dummy pattern 150 c 1 between the dielectric dummy patterns 150 c has a square-wave shape with a fixed width W6.

As shown in FIG. 4F, in some embodiments, dielectric dummy patterns 150 d embedded in the conductive line 134 of the structure 500 h are rectangular and are parallel to each other. Each of the dielectric dummy patterns 150 d has a length L1 and a width W4. In some embodiments, the length L1 of each of the dielectric dummy patterns 150 d is less than the total length of the conductive line 134. In some embodiments, the width W4 of each of the dielectric dummy patterns 150 d is less than a width Wb of the conductive line 134 shown in FIG. 3. The length direction of the dielectric dummy patterns 150 d is substantially along the extending direction of the conductive line 134. In some embodiments, the dielectric dummy patterns 150 d are arranged as a two-row array.

As shown in FIG. 4F, in some embodiments, dielectric dummy patterns 150 e of the structure 500 i are triangular. In some embodiments, the boundaries 152 e 2 of the dielectric dummy patterns 150 e are parallel to each other. In addition, the boundaries 152 c 1 of the dielectric dummy patterns 150 e that are close to each other are parallel to each other.

As shown in FIG. 4H, in some embodiments, dielectric dummy patterns 150 f embedded in the conductive line 134 of the structure 500 j are rectangular and are parallel to each other. The dielectric dummy patterns 150 f are separated from each other and are periodically arranged with a fixed pitch.

As shown in FIG. 4I, in some embodiments, the shape of the dielectric dummy patterns 150 g of the structure 500 k is similar to the shape of the dielectric dummy patterns 150 f of the structure 500 j. In some embodiments, the two dielectric dummy patterns 150 g close to each other are arranged in a group. The dielectric dummy patterns 150 g are arranged in multiple groups. The groups of the dielectric dummy patterns 150 g are periodically arranged with a fixed pitch P1.

As shown in FIG. 4J, in some embodiments, dielectric dummy patterns 150 h embedded in the conductive line 134 of the structure 500 l are circular. The dielectric dummy patterns 150 h have a diameter W8 that is less than the width of the dielectric dummy patterns 150 h shown in FIG. 3. The dielectric dummy patterns 150 h are periodically arranged as a two-row array.

As shown in FIG. 4K, in some embodiments, the shape of dielectric dummy patterns 150 i of the structure 500 m is similar to the shape of the dielectric dummy patterns 150 h of the structure 500 l. In some embodiments, the six dielectric dummy patterns 150 i close to each other are arranged in a group. The dielectric dummy patterns 150 i are arranged in multiple groups. The groups of the dielectric dummy patterns 150 i are periodically arranged with a fixed pitch P2.

As shown in FIG. 4L, in some embodiments, the shape of dielectric dummy patterns 150 j of the structure 500 n is similar to the shape of the dielectric dummy patterns 150 h of the structure 500 l. In some embodiments, the dielectric dummy patterns 150 j are arranged as a four-row array.

As shown in FIG. 4M, in some embodiments, the shape of dielectric dummy patterns 150 k of the structure 500 p is similar to the shape of the dielectric dummy patterns 150 h of the structure 500 l. In some embodiments, the dielectric dummy patterns 150 k are arranged as a four-row array.

Embodiments for a hybrid-bonding structure (e.g. the hybrid-bonding structures 600A-600B) and a method for forming the same are provided. The hybrid-bonding structure includes a first semiconductor substrate (e.g. the substrate 100 of the structure 500 a of the hybrid-bonding structure 600A, the substrate 200 of the first structure 500 b of the hybrid-bonding structure 600B and the substrates 100 or 200 of the structure 500 c-500 n and 500 p). The hybrid-bonding structure further includes a first conductive line (e.g. the conductive line 132 and the conductive line 134) and a first dielectric dummy pattern (e.g. the dielectric dummy patterns 150 and 150 a-150 k) over the first semiconductor substrate. A surface 136 of the first conductive line is configured to hybrid-bond with a second conductive line (e.g. the conductive line 132 of the structure 500 a′ of the hybrid-bonding structure 600A or the bonding layer 220 of the second structure 300 of the hybrid-bonding structure 600B) over a second semiconductor substrate (e.g. the substrate 100 of the structure 500 a′ of the hybrid-bonding structure 600A or the second substrate 302 of the hybrid-bonding structure 600B). The first dielectric dummy pattern is embedded in the first conductive line. The dielectric dummy patterns 150 embedded in the conductive line help to reduce the area of the top surface 136 of the conductive line 132. The dielectric dummy patterns 150 can improve the surface topography of the bonding surface 154 of the conductive line 132 after performing the planarization process 131 of the conductive line 132. When the first conductive line of the first structure is hybrid-bonded to the second conductive line of a second structure (e.g. the structure 500 a′ of the hybrid-bonding structure 600A or the second structure 300 of the hybrid-bonding structure 600B), the dielectric dummy patterns 150 may contribute to the bond strength between the first conductive line of the first structure and the second conductive line of the second structure. The bonding surface 154 of the conductive line 132 having a planarized surface topography can improve the bonding wave propagation during the hybrid-bonding process. The delamination problem and the conductive line opening problem that occurs between the first conductive line of the first structure and the second conductive line of the second structure are avoided. The dielectric dummy patterns can be embedded in long and wide conductive lines, such as the bonding layer of the seal ring structure or the bonding layer in 3DICs and MEMS applications.

Embodiments for a hybrid-bonding structure and a method for forming the same are provided. The hybrid-bonding structure includes a first semiconductor substrate. The hybrid-bonding structure further includes a first conductive line and a first dielectric dummy pattern over the first semiconductor substrate. A surface of the first conductive line is configured to hybrid-bond with a second conductive line over a second semiconductor substrate. The first dielectric dummy pattern is embedded in the first conductive line. The dielectric dummy patterns embedded in the conductive line help to improve the surface topography of the bonding surface of the conductive line after performing the planarization process of the conductive line. The dielectric dummy patterns may contribute to the bond strength of the hybrid-bonding structure. The dielectric dummy patterns can be embedded in the bonding layer of the seal ring structure or the bonding layer in 3DICs and MEMS applications.

In some embodiments, a method for forming a hybrid-bonding structure is provided. The method includes forming a first dielectric layer over a first semiconductor substrate. The first semiconductor substrate includes a conductive structure. The method also includes partially removing the first dielectric layer to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern and an opening through the first dielectric layer. The first dielectric dummy pattern, the second dielectric dummy pattern and the third dielectric dummy pattern are surrounded by the opening. In addition, the method includes forming a first conductive line in the opening. The first conductive line is in contact with the conductive structure.

In some embodiments, a method for forming a hybrid-bonding structure is provided. The method includes forming a first dielectric layer over a first seal ring structure. The method also includes removing a portion of the first dielectric layer to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern and an opening through the first dielectric layer. In addition, the method includes forming a seed layer at a bottom surface and a sidewall of the opening. The method further includes forming a conductive material over the seed layer. The seed layer and the conductive material forms a first conductive line in the opening.

In some embodiments, a method for forming a hybrid-bonding structure is provided. The method includes forming a first dielectric layer over a first substrate. The method also includes removing portions of the first dielectric layer to form a first plurality of dielectric dummy patterns and a first opening surrounding the first plurality of dielectric dummy patterns. In addition, the method includes forming a first conductive line in the first opening, forming a second dielectric layer over a second substrate, and removing portions of the second dielectric layer to form a second plurality of dielectric dummy patterns and a second opening surrounding the second plurality of dielectric dummy patterns. The method also includes forming a second conductive line in the second opening. The method further includes bonding the first conductive line to the second conductive line. The first plurality of dielectric dummy patterns is in contact with the second plurality of dielectric dummy patterns to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern after bonding. The second dielectric dummy pattern is located between the first dielectric dummy pattern and the third dummy pattern, and a maximum distance between the first dielectric dummy pattern and the second dielectric dummy pattern is greater than a maximum distance between the second dielectric dummy pattern and the third dielectric dummy pattern.

The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. 

What is claimed is:
 1. A method for forming a hybrid-bonding structure, comprising: forming a first dielectric layer over a first semiconductor substrate, wherein the first semiconductor substrate comprises a conductive structure; partially removing the first dielectric layer to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern and an opening through the first dielectric layer, wherein the first dielectric dummy pattern, the second dielectric dummy pattern and the third dielectric dummy pattern are surrounded by the opening; and forming a first conductive line in the opening, wherein the first conductive line is in contact with the conductive structure.
 2. The method for forming a hybrid-bonding structure as claimed in claim 1, wherein forming the first conductive line in the opening comprises: depositing a conductive material to fill the opening; and removing the conductive material outside the opening.
 3. The method for forming a hybrid-bonding structure as claimed in claim 2, further comprising: depositing a seed layer to line the opening before depositing a conductive material to fill the opening.
 4. The method for forming a hybrid-bonding structure as claimed in claim 1, wherein the opening exposes the conductive structure.
 5. The method for forming a hybrid-bonding structure as claimed in claim 1, further comprising: forming a second dielectric layer over a second semiconductor substrate, wherein the second semiconductor substrate comprises a second conductive structure; partially removing the second dielectric layer to form a fourth dielectric dummy pattern, a fifth dielectric dummy pattern and a sixth dielectric dummy pattern and a second opening through the second dielectric layer, wherein the fourth dielectric dummy pattern, the fifth dielectric dummy pattern and the sixth dielectric dummy pattern are surrounded by the second opening; forming a second conductive line in the second opening, wherein the second conductive line is in contact with the second conductive structure; and bonding the first conductive to the second conductive line.
 6. The method for forming a hybrid-bonding structure as claimed in claim 5, wherein the first dielectric dummy pattern is in contact with the fourth dielectric dummy pattern, the second dielectric dummy pattern is in contact with the fifth dielectric dummy pattern, and the third dielectric dummy pattern is in contact with the sixth dielectric dummy pattern.
 7. The method for forming a hybrid-bonding structure as claimed in claim 1, wherein forming the first dielectric layer comprises: forming a first dielectric sublayer over the first semiconductor substrate; and forming a second dielectric sublayer over the first dielectric sublayer, wherein the first dielectric sublayer and the second dielectric sublayer are made of different materials.
 8. The method for forming a hybrid-bonding structure as claimed in claim 1, wherein the second dielectric dummy pattern is located between the first dielectric dummy pattern and the third dummy pattern, and a maximum distance between the first dielectric dummy pattern and the second dielectric dummy pattern is greater than a maximum distance between the second dielectric dummy pattern and the third dielectric dummy pattern.
 9. The method for forming a hybrid-bonding structure as claimed in claim 8, wherein the first dielectric dummy pattern, the second dielectric dummy pattern, and the third dielectric dummy pattern are aligned in a straight line in a first direction, and no dielectric material is formed between the first dielectric dummy pattern and the second dielectric dummy pattern and between the second dielectric dummy pattern and the third dielectric dummy pattern along the first direction.
 10. A method for forming a hybrid-bonding structure, comprising: forming a first dielectric layer over a first seal ring structure; removing a portion of the first dielectric layer to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern and an opening through the first dielectric layer; forming a seed layer at a bottom surface and a sidewall of the opening; and forming a conductive material over the seed layer, wherein the seed layer and the conductive material forms a first conductive line in the opening.
 11. The method for forming a hybrid-bonding structure as claimed in claim 10, wherein the first seal ring structure comprises: a plurality of conductive layers; and a plurality of vias alternately arranged with the plurality of conductive layers, wherein the first conductive line is in contact with a topmost conductive layer of the plurality of the conductive layer of the seal ring structure.
 12. The method for forming a hybrid-bonding structure as claimed in claim 10, further comprising: forming a second dielectric layer over a second seal ring structure; forming a second conductive line through the second dielectric layer and electrically connected to the second seal ring structure, wherein the second conductive line surrounds a fourth dielectric dummy pattern, a fifth dielectric dummy pattern and a sixth dielectric dummy pattern of the first dielectric layer; and bonding the first conductive to the second conductive line.
 13. The method for forming a hybrid-bonding structure as claimed in claim 10, wherein the second dielectric dummy pattern is located between the first dielectric dummy pattern and the third dummy pattern, and the first dielectric dummy pattern, the second dielectric dummy pattern, and the third dielectric dummy pattern are aligned in a straight line in a first direction.
 14. The method for forming a hybrid-bonding structure as claimed in claim 13, wherein a maximum distance between the first dielectric dummy pattern and the second dielectric dummy pattern is greater than a maximum distance between the second dielectric dummy pattern and the third dielectric dummy pattern.
 15. The method for forming a hybrid-bonding structure as claimed in claim 14, wherein no dielectric material is formed between the first dielectric dummy pattern and the second dielectric dummy pattern and between the second dielectric dummy pattern and the third dielectric dummy pattern along the first direction.
 16. A method for forming a hybrid-bonding structure, comprising: forming a first dielectric layer over a first substrate; removing portions of the first dielectric layer to form a first plurality of dielectric dummy patterns and a first opening surrounding the first plurality of dielectric dummy patterns; forming a first conductive line in the first opening; forming a second dielectric layer over a second substrate; removing portions of the second dielectric layer to form a second plurality of dielectric dummy patterns and a second opening surrounding the second plurality of dielectric dummy patterns; forming a second conductive line in the second opening; and bonding the first conductive line to the second conductive line, wherein the first plurality of dielectric dummy patterns is in contact with the second plurality of dielectric dummy patterns to form a first dielectric dummy pattern, a second dielectric dummy pattern and a third dielectric dummy pattern after bonding, wherein the second dielectric dummy pattern is located between the first dielectric dummy pattern and the third dummy pattern, and a maximum distance between the first dielectric dummy pattern and the second dielectric dummy pattern is greater than a maximum distance between the second dielectric dummy pattern and the third dielectric dummy pattern.
 17. The method for forming a hybrid-bonding structure as claimed in claim 16, wherein the first dielectric dummy pattern, the second dielectric dummy pattern, and the third dielectric dummy pattern are aligned in a straight line in a first direction, and no dielectric material is formed between the first dielectric dummy pattern and the second dielectric dummy pattern and between the second dielectric dummy pattern and the third dielectric dummy pattern along the first direction.
 18. The method for forming a hybrid-bonding structure as claimed in claim 16, further comprising: forming a fourth dielectric dummy pattern next to the first dielectric dummy pattern after bonding, wherein a maximum distance between the first dielectric dummy pattern and the fourth dielectric dummy pattern is substantially equal to the maximum distance between the second dielectric dummy pattern and the third dielectric dummy pattern.
 19. The method for forming a hybrid-bonding structure as claimed in claim 18, further comprising: forming a fifth dielectric dummy pattern next to the fourth dielectric dummy pattern after bonding, wherein a lengthwise direction of the fifth dielectric dummy pattern is perpendicular to a lengthwise direction of the first dielectric dummy pattern.
 20. The method for forming a hybrid-bonding structure as claimed in claim 19, wherein a maximum distance between the fourth dielectric dummy pattern and the fifth dielectric dummy pattern is greater than a maximum distance between the first dielectric dummy pattern and the fourth dielectric dummy pattern. 